1,720,968 research outputs found
Spanish Broom (Spartium junceum L.) as New Fiber for Biocomposites: The Effect of Crop Age and Microbial Retting on Fiber Quality
Full text linkIn field non-invasive sensing of the nitrogen status in hybrid bermudagrass (Cynodon dactylon × C. transvaalensis Burtt Davy) by a fluorescence-based method
Full text linkThe level of N fertilization and the content of leaf N in Cynodon dactylon × C. transvaalensis Burtt Davy cv. ‘Tifway 419’ bermudagrass were evaluated non-destructively with a fluorescence-based method. It was applied directly into the field by using the Multiplex portable fluorimeter during two consecutive seasons (2010 and 2011). In the 2010 experiment, the nitrogen balance index (NBI1) provided by the sensor was able to discriminate (at P < 0.05) six different N levels applied, up to 250 kg ha−1, with a precision (root mean square error, RMSE) in the rate estimate of 3.29 kg ha−1. In 2011, the index was insensitive to the N treatment between 150 kg ha−1 and 250 kg ha−1 N rates, and its precision was 39.98 kg ha−1. Calibration of the sensor by using the destructive analysis of turf samplings showed a good linear regression between NBI1 and the leaf N content for both 2010 (R2 = 0.81) and 2011 (R2 = 0.93) experiments. This allowed mapping of the leaf N spatial distribution acquired by the sensor in the field with a prediction error of 0.21%. Averaging the overall estimates of leaf N content per N treatment provided an upper limit of 200 kg ha−1 for the required fertilization, corresponding to a critical level of leaf N of about 2.3%. Our results confirm the usefulness of the new fluorescence-based method and sensor for a precise management of fertilization in turfgrass
EVALUATION OF CAMELINA SATIVA (L.) CRANTZ AS OILSEED CROP IN TWO ENVIRONMENTS OF CENTRAL AND NORTHERN ITALY
No full textCamelina (Camelina sativa (L.) Crantz) has gained considerable attention in Europe and North America as a
potential oilseed feedstock for advanced biofuels (i.e.aviation fuel) and bioproducts. Camelina seeds contain also different compounds, among which glucosinolates (GLs) make the resulting oil cake interesting for the production of value added chemicals . The objectives of the following study were to characterize the production potential of camelina in two environments of central (Pisa, Tuscany) and northern (Bologna, Emilia Romagna) Italy, traditionally devoted to cereal and
sunflower cultivation. Results showed that seed and oil yield were higher in Pisa than in Bologna. This was probably due to differences in the sowing dates. In fact, previous experiments showed that winter sown camelina can be damaged by frost in the initial vegetative growth stages. The harvest index found in Pisa was significantly higher than in
Bologna due to the lower dry matter accumulation in the vegetative tissues in spring sown crops during the 2nd
and 3rd year of field trial. Very high amounts of GLs were found, with significant variation among years and
environments ; the values reached in both environments were among the highest between those found in
the literature.This study highlights the good crop adaptability, seed and oil yield, protein and GL content of camellia under the pedo-climatic conditions of central and northern Italy, evidencing a clear effect of location and climate on
seed yield and its quality. The high amount of glucosinolates makes the resulting oil cake suitable for the
production of value added chemicals
Novel oilseed crops for cropping systems diversification in Central Italy
No full textThe traditional cereal-based systems of the lowland environments of Mediterranean region are subject to progressive degradation and undesirable decrease in their fertility. Diversification through crop rotation could lead to a more sustainable production systems, in accordance also with the greening measures of the new EU CAP (2014–2020). For farmers, it is crucial to find new crops to include in crop rotations. Novel oilseed crops, like linseed (Linum usitatissimum L.), safflower (Carthamus tinctorius L.), garden cress (Lepidium sativum L.), camelina (Camelina sativa (L.) Crantz) and sesame (Sesamum indicum L.) may represent a valuable alternative, due to their adaptability to marginal soils and to their economic value related to the high quality of the oil, increasingly appreciated by consumers and by the industry . The aim of the present study was to investigate the production potential of winter (garden cress, safflower and linseed) and spring (camelina and sesame) novel oilseed crops at farm level in central Italy in integrated production systems. Results showed that in safflower and linseed, seed, oil and straw yields were significantly influenced by the year of cultivation, while yields of garden cress and camelina were quite stable throughout the study . Significant differences in the oil content were found only for camelina with a significant reduction in 2015. Linseed showed an oil content and yield comparable to sunflower. The oil quality of both crops compared well with market standards, with a content of linoleic >72% and linolenic > 57% in safflower and linseed respectively.The oil of garden cress was characterized by a similar level of oleic and linolenic acid. Camelina showed an interesting oil content and yield, in particular in the first two years of experiments, with a high content of linolenic acid and a medium level of erucic acid. Sesame oil showed a fatty acid composition characterised by high oleic (36.4%) and linoleic acid (46.9%) content that makes this oil nutritionally beneficial.This study underlined the possibility to successfully grow and handle novel oilseed crops in the studied pedoclimatic conditions where they can be included in a rotation scenario with wheat. These oilseed crops showed good adaptability, with quite stable yields over the years and interesting oil content and composition for possible industrial applications. Furthermore, they can contribute to preserve soil fertility and its long-term maintenance by reducing erosion and nutrient losses during the rainy season, and /or by organic carbon sequestration through soil incorporation of crop residues
Turfgrass spectral reflectance: simulating satellite monitoring of spectral signatures of main C3 and C4 species
No full textIn recent years, within the European Union several legislative, monitoring and
coordinating actions have been undertaken to encourage sustainable use of resources,
reduction in the use of chemicals and improvement of the urban environment. In this
respect, two concepts that are strictly related to most of the aspects above are: ‘‘precision
agriculture’’ and ‘‘precision conservation’’ and more specifically ‘‘precision turfgrass
management.’’ Optical sensing has become a crucial part of precision turfgrass management
and spectral reflectance in particular has been an active area of research for many
years. However, while turfgrass status evaluation by proximity-sensed spectral reflectance
appears to be an established and reliable practice, much more could be achieved in terms of
monitoring of large turfgrass areas through remote sensing, and in particular through
satellite imagery. This paper reports the results of a trial attempting to evaluate the spectral
signatures of several turfgrass species and cultivars, for future use in turfgrass satellite
monitoring. Our experimental study focused on 20 turfgrass species/varieties including
perennial ryegrasses, tall fescues, kentucky bluegrasses, bermudagrass ecotypes, seeded
commercial bermudagrasses, vegetatively propagated bermudagrasses, Zoysia japonica
and non-japonica zoysiagrasses. Various biological and agronomical parameters were
studied and turfgrass spectral reflectance for all entries was gathered. Vegetation indices
were calculated by simulating the available wavelengths deriving from World View 2
satellite imagery. Results showed that within the same species selected vegetation indices
are often able to discriminate between different varieties that have been established and
maintained with identical agronomical practice
Monitoring turfgrass species and cultivars by spectral reflectance
Full text linkLike all modern agriculture sectors, turfgrass productionand management is headed towards cost reduction, resourceoptimization and reduction of the environmentalimpact. In recent years the development of newtechnologies has provided new tools for monitoringagricultural crops. In particular, the combined adoptionof geographic information systems, global positioningsystems, multispectral lenses on board satellitesand cartographic techniques allow a large scalemanagement of agricultural resources. This paper reportsthe results of a trial attempting to evaluate thespectral signatures of several turfgrass species\cultivars,for future use in satellite monitoring. This experimentalstudy focused on 20 turfgrass species\cultivars,including perennial ryegrasses, tall fescues, kentuckybluegrasses, bermudagrasses (ecotypes, seededand vegetatively propagated cultivars) and zoysiagrasses.Various agronomical and biological parameterswere studied (quality, colour, dry matter, chlorophyll,carotenoids, nitrogen content) and turfgrass spectralreflectance for all entries was gathered. Results showedthat, within the same species, selected vegetation indicesare often able to discriminate between differentcultivars that have been established and maintainedwith identical agronomical practices. Evaluation ofthe spectral reflectance of plants using field spectroradiometryprovides the possibility to identify differentspecies\ cultivars, especially through the use of hyperspectralproximity and remote sensing
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
